Punch assembly



R. GOLDMAN PUNCH ASSEMBLY Jan. 24, 71967 3 Sheets-Sheet 1 Filed Nov. 6, 1964 III/z VIII/III!!! lNVENTOf? RUBIN GOLDMAN N9 N9 382% 582% :9: 20$ 00. Q9 382% Ivi; ,i 582% 20mm 231m ATTORNEYS Jan. 24, 1967 3 Sheets-Sheet 2 Filed Nov. 6, 1964 ATTORNEYS R. GOLDMAN PUNCH AS SEMBLY Jan. 24, 1967 3 Sheets-Sheet 5 306 Filed Nov. 6, 1964 RUBIN GOLDMAN 9/ Wad/M United States Patent 3,299,761 PUNCH ASSEMBLY Rubin Goldman, 22 Park Drive, Newton Highlands, Mass. 02161 Filed Nov. 6, 1964, Ser. No. 409,415 15 Claims. (Cl. 83-639) This invention relates to punching apparatus and more particularly comprises a new and improved multi-punch assembly for perforating thin sheet stock. The device may include as a part thereof a knife for simultaneously slitting the stock as it is perforated.

In recent years polyethylene bags have come into widespread use to package such diverse products as food stuffs, clothing and scientific instruments. In certain of such uses, it is necessary to provide perforations in the bags to allow air to circulate about the goods packaged in them. To form the perforations most economically in the plastic sheet material of the bags, it is customary to mount on the bag making machines auxiliary equipment which will perform the punching operations while the bag making machines cut, fold and seal the edges of the sheet to form the bags.

One important object of this invention is to provide a multi-punch assembly for use on bag making machines which may be readily adjusted to vary the positions of the holes formed in the sheet material passing through the punch assembly.

Another important object of this invention is to provide a punch assembly which is capable of simultaneously punching very closely spaced holes in a sheet moving through the assembly.

Another important object of this invention is to provide a multi-punch assembly which is relatively inexpensive to manufacture and which is capable of giving long trouble free service.

Yet another important object of this invention is to provide a multi-punch assembly which can simultaneously punch and slit the sheet material which passes through it.

Still another important object of this invention is to provide a control system for a multi-punch assembly, which has a minimum number of moving parts, is free of all costly electrical control elements and which may be serviced and adjusted by a technician with limited training.

To accomplish these and other objects, the multi-punch assembly of this invention includes a frame which supports a plurality of independent punch mechanisms each capable of perforating sheet material passed through the assembly. A pneumatic control system is connected to each of the punches for simultaneously actuating all of the punches to form a plurality of perforations in the sheet. In one of the embodiments of this invention the punch carries a slitting knife which is simultaneously actuated with the punch to form a cut in the material adjacent the perforation.

These and other objects and features of this invention along with its incident advantages will be better understood and appreciated from the following detailed description of two embodiments thereof, selected for purposes of illustration and shown in the accompanying drawing, in which:

FIG. 1 is a front elevation view, partly in section, showing one embodiment of a multi-punch assembly constructed in accordance with this invention;

FIG. 2 is an end view of the assembly of FIG. 1 with the pneumatic control system shown diagrammatically;

FIG. 3 is a cross-sectional view of a control valve forming part of the pneumatic control system;

FIG. 4 is a perspective view of another embodiment of this invention;

FIG. 5 is a cross-sectional view of one of the punch units in the assembly shown in FIG. 4;

FIG. 6 is a cross-sectional view taken along the corresponding section line in FIG. 5; and

FIG. 7 is a plan view of a sheet punched and cut by the apparatus of FIGS. 4-6.

In FIG. 1 but two of a plurality of punch units are shown mounted in the assembly. The assembly shown includes a pair of blocks 10 which comprise part of its frame, and the blocks 10 in turn are shown secured to a pair of angle irons 12 on opposite sides of the assembly by mounting clamps 14 screwed to the lower surface of the blocks. The angle irons 12 represent a portion of the frame of a bag making machine or some similar machine on which the multi-punch assembly is used as auxiliary equipment. Therefore, the angle irons 12 and the frame that they represent form no part of the present invention.

Three independent frame members 16, 18 and 20 extend between the blocks 10. The member 16 serves as a cylinder holder, the member 18 as a punch holder, and the member 20 as a die holder. The members 18 and 20 are secured to the blocks 10 by screws 22 and bolts 24 which pass through the blocks 10, the ends of the member 18, spacers 26 and the lower member 20. The top member 16 is secured to the upper surface of the blocks 10 by screws 28 that pass through the web 30 of the member 16 and are anchored in the blocks. It will be noted in FIGS. 1 and 2 that the member 16 is an angle having a front flange 34 and web 30. The members 16, 18 and 20 are precisely aligned with one another on the block 10 by means of the dowel assemblies 36.

In FIG. 1 it will be noted that each of the two punch units 40 is generally composed of three parts; namely, a cylinder unit 42, punch unit 44 and die unit 46. The cylinder unit 42 includes a body 48 having a downwardly extending externally threaded collar 50 which is mounted in a hole 52 in the web 30 of the member 16 by nut 54 threaded onto the collar 50. Plunger 56 extends out of the collar 50 below the web 30 and serves as a direct actuator for the punch unit 44. The cylinder unit-42 is pneumatically actuated by a control system which will be described in detail below.

The punch unit 44 is slidably mounted in a bushing 58 which lines the opening 69 in the punch holder 18. Each opening 60 in the holder 18 is shown lined with its own bushing. The punch body 62 is biased to an elevated position as shown in FIG. 1 by spring 64 which bears against the upper surface of the bushing 58 and a ring 66 secured to the top of the punch body.

A cavity 68 is provided in the lower end of the punch body 62, which cavity is defined by a circular skirt 70. A hardened steel backer 72 is mounted in the top of the cavity 68, and the ball 74 of the punch is spun into the cavity or the lower end of the skirt is struck over to retain the ball in place.

The die unit 46 includes a die button 76 having its upper surface substantially in the plane of the upper surface 78 of the die holder 20. The die button 76 is in the form of a sleeve having a sharp upper inner edge 80 which cooperates with the ball 74 to perform the cutting operation. In FIG. 1 it will be noted that the openings 82 in the die holder 20 Which receive the buttons 76 have an upper portion 84 of smaller diameter in which the die buttons 76 are mounted. The lower portion of each opening 82 is of larger diameter and is threaded, and an adjusting screw 86 supports the die button 76 at the correct elevation in the upper portion 84 of the opening. The adjusting screw enables the operator to periodically raise the die button 76 as wear takes place with contined use of the mechanism, and to compensate for regrinding of the upper surface of the button to sharpen the cutting edge 80.

In the assembly of FIG. I, the frame members or holders 16, 18 and 20 are shown broken to shorten the illustration, and but five sets of openings each including one each of openings 52, 60 and 82 are shown provided in the three members, respectively. In the actual assembly some sixteen sets of holes are provided in the members so that sixteen punch units can be simultaneously mounted on the assembly to form holes in material fed through the assembly. The material being punched is normally fed through the assembly on the upper surface 78 of the die holder 20, and the material being punched is advanced between actuations of the punches.

In FIG. 2 the control mechanism for actuating the punches is illustrated. In that figure three manifolds 100, 102 and 104 are shown disposed behind the cylinder unit 42 in stepped arrangement. The manifolds 100, 102 and 104 are made from square aluminum extrusions with a hole extruded in the center. The extrusions are held together by clamps made from bent plates bolted together along their edges. The manifold assembly is secured to the blocks 10 by blots 105.

The cylinder unit 42 as shown in FIG. 2 carries an impulse valve 106 which is shown in detail in FIG. 3. The impulse valve controls the flow of air to the cylinder 42 so as to control the actuation of its plunger 56. When the valve 106 is opened air is directed into the cylinder 42 above its piston (not shown), and its plunger 56 strikes the punch body 62. The valve 106 is of standard design and is extremely beneficial in the system.

The valve 106 is shown to have an inlet fitting 108 adapted to be connected to a compressed air source and an outlet fitting 110 which in FIG. 2 is shown secured to the top of the cylinder 42. Flow from inlet fitting 108 is through passage 112 in the body and an opening 114 in the rubber diaphragm 116 to chamber 118. When the rubber diaphragm moves to the right as shown in FIG. 3 it forms a gap between its conical portion 120 and the valve seat 122, and air may flow directly from the passage 112 into the axial passage 124 in the body which in turn communicates with the outlet fitting 110.

A control fitting 126 secured to the body of valve 106 is also adapted to be secured to a compressed air source. When so connected, air under pressure is directed against the left face of another diaphragm 128 mounted on the left end of passage 124. The diaphragm 128 is mounted in tandem with the diaphragm 116 by means of the pin connection 130, and when the pressure exerted against the left face of the diaphragm 128 exceeds the pressure exerted against the right face of the diaphragm 116 from chamber 118, the conical portion 120 of the diaphragm 116 removes from the seat 122, and the inlet and outlet fittings 108 and 110 are placed in communication with one another. Thus it is seen that in FIG. 2 compressed air may be directed through the impulse valve 106 from the inlet fitting 108 to the outlet fitting 110 so as to activate the cylinder 42 to lower the plunger 56 when the fitting 126 is connected to a compressed air source.

In FIG. 2 the fitting 126 is shown schematically to be connected to an outlet fitting 132 on the second manifold 102 by duct 133. An outlet fitting 134 on the manifold 104 is shown connected to the inlet fitting 108 of the impulse valve 106 by duct 135. The center manifold 102 is in turn connected to a compressed air source by means of a duct 136 shown achematically which may be controlled by a solenoid valve 138. The manifolds and 104 are connected to a compressed air source through lines 140 and 142, which respectively contain shut off valves 144 and 146. It will also be noted in FIG. 2 that a pressure regulator valve 148 and a gage 150 are provided in the line 135 connecting the manifold 104 to the fitting 108 of the impulse valve 106.

As suggested above, one of the advantages of this invention is the ability to place a plurality of punches in very close proximity to one another on the assembly. It Will be noted in FIG. 1 that the openings in the members 16, 18 and 20 are closely spaced so that when punch units are mounted in each of the sets of openings the cylinders of the different units almost touch one another. In order to control each of the punches effectively, and not crowd or complicate the hose connections between the manifolds and the impulse valves, the manifolds 100 and 104 are alternately connected to the punch units. Thus, every other punch unit may be connected to the manifold 104 in the manner shown in FIG. 2, and the intervening punch units may be connected to the manifold 100 by means of the line 152. It will be noted in FIG. 2 that the line 152 contains a pressure regulator 154 and a gage 156 identical to the gages in the line 135 from the manifold 104. However, the manifold 102 controls the actuation of each of the impulse valves of the punch units. Thus, in FIG. 1 the impulse valves 106 are shown each to be controlled by manifold 102. However, one of the valves 106 is connected to a compressed air source which operates the cylinder through manifold 104 While the other is connected through manifold 100. Ordinarily the valves 144 and 146 in the lines to the manifolds 100 and 104 are open and consequently air under pressure is available to operate the cylinders at the impulse valves 106. The fittings 126 of the impulse valves are all connected to the manifold 102, and they are in turn simultaneously controlled by the solenoid valve 138. When the solenoid valve 138 opens directing air under pressure to the manifold 102, the impulse valves 106 are in turn opened by the pressure exerted on their diaphragms 128. Consequently all of the punch units 44 are simultaneously actuated as their respective impulse valves are opened. When the solenoid 138 is closed springs 158 in the impulse valves reseat the conical valves 120 on the seats 122 and no more compressed air is delivered through the impulse valves to the tops of the cylinders. The cylinder plungers 56 are in turn returned to the raised position by springs (not shown) within the cylinder bodies.

Because the several manifolds 100, 102 and 104 ex tend substantially the full length of the frame members or holders 16, 18 and 20, the outlet fittings from the manifolds 100 and 104 are conveniently spaced along the manifolds behind the blocks 10, and it is easy to connect and disconnect the several ducts from those manifolds leading to the inlet fittings of the impulse valves. Further the center manifold 102 is provided with a series of outlet fittings 132 Which are relatively closely spaced and which are connected by ducts to the fittings 126 of each of the impulse valves. The individual ducts or lines connected between the manifold and the impulse valves are relatively short and do not have a tendency to become tangled or twisted, which would make repair difiicult.

It will be appreciated that the manifold 102 is provided with an outlet fitting for each of the stations defined by the sets of openings in the members 16, 18 and 20. However, the pliable plastic hoses are made long enough so that it is unnecessary to disconnect the hoses from the manifold each time an assembly is moved from one station to another. It is apparent that the punch units themselves may be conveniently transferred from station to station in the assembly. By unscrewing the lock nuts 54 the cylinder units may be transferred from opening to opening in the member 16. The punch units 44 may be transferred from one bushing 58 to another in the openings 60 provided in the member 18, and the dies may be transferred from opening to opening merely by removing the adjusting screws 86 and droping the die buttons into another of the openings.

The embodiment of FIG. 4 differs from that of FIG. 1 in several respects. First, while the punch units of the assembly of the embodiment of FIG. 1 merely punch holes in the stock fed through the assembly, the punch units of the embodiment of FIG. 4 both punch and slit the sheet material as suggested in FIG. 7. In FIG. 7 a fragment 200 of a plastic sheet is shown provided with a hole 202 and a slit 204 which are simultaneously formed in the sheet by the unit of FIG. 4. Further, the assembly of FIG. 4 is composed of two punch units which may be moved toward and away from each other on a mounting bar 206 in an infinite variety of positions.

In FIG. 4 the mounting bar 206 is shown to be slidably mounted on a rod 208 which passes through a hole 210 at the right end of the bar. A similar hole not visible in FIG. 4 receives another rod 212 on the left side of the unit. In FIG. 5 one end 214 of rod 212 is shown secured to a channel member 216 by a C-clamp 218. The channel 216 represents a portion of the frame of a bag making machine or other machine on which the assembly of FIG. 4 is used as auxiliary equipment.

The two punch units 220 and 222 mounted on the mounting bar 206 are identical and one is shown in detail in FIG. 5. The unit 220 is shown in FIG. 5 to include a post 224 which is vertically oriented and slidable horizontally along the mounting bar 206. A recess 226 in the post 224 receives the front face 228 of the mounting bar 206, and a mounting clamp 230 is secured at the top and bottom by screws 232 and 234 to the rear surface of the post 224 about the bar 206. By loosening the top screw 232, the gripping surface 236 of the clamp may be moved away from the rear surface of the bar 206 so that the unit 220 may slide horizontally on the bar. To secure the unit fast in a fixed position on the bar it is only necessary for the operator to tighten the screw 232.

A cylinder 238 is carried on an angle bracket 240 secured to the block 242 bolted to the upper portion of the post 224. The cylinder 238 may be removed from the horizontal arm of the bracket 240 by unscrewing the nut 244.

A punch unit 246 is carried by a punch holder 248 mounted on the post 224 below the block 242. Like the previously described embodiment, the holder 248 is provided with a bushing 250 seated in a hole in the holder 248, which slidably receives punch body 252. The punch body 252 is urged to an elevated position by a spring 254 which surrounds the upper portion of the body and bears against the top of the bushing 250 and a ring 256 secured to the punch body adjacent its top. A keyway 258 in the side of the punch body 252 receives a key 260 carrying a locking nut, which passes through an opening in the bushing 250 and a threaded hole in the holder 248, to prevent the punch body 252 from turning in the bushing. Alternatively, alignment of the punch body may be maintained by such means as posts extending upwardly on the lower end of the body, which register with holes in the holder 248.

The lower end of the body 252 is enlarged and includes an axial cavity 262 in its bottom defined by a surrounding skirt 264. A hardened backup plate 266 is provided in the cavity and the punch ball 268 is retained in the cavity by a hardened ring 270 screwed to the skirt 264 by screws 272.

The enlarged lower portion of the punch body 252 also carries a cutting blade 274 in vertical slot 275, which is supported by a backup plate 276. The blade 274 may be of a variety of shapes and may be designed to make either a single cut or a series of short serrations, and the cuts may extend either to the edge of the sheet being cut or alternatively the cuts may be positioned inwardly of the edge as shown in FIG. 7. The blade 274 is retained in place by a hose-type clamp 280 which surrounds the lower portion of the body as is clearly shown in FIG. 6. It will be noted in FIG. 5 that the retaining ring 270 has a somewhat greater diameter than the lower portion of the body to prevent the clamp from sliding downwardly off the enlarged lower end.

Below the punch unit 246 a die holder 282 is bolted by means of screw 284 to the post 224. The die holder 282 is provided with an opening 286 aligned axially with the punch. The die button 288 is positioned in the opening 286 by an adjustable screw 290 and lock nut 292. In FIG. 5 it will be noted that the screw 290 is threaded into the lower end of the opening 286 and supports the bottom of the die button 288.

An inclined slot 294 is formed in the die holder 282 and extends radially from the opening 286. The slot 294 is aligned with the blade 274 so as to receive the blade when the punch body 252 is driven downwardly by the cylinder 238. In FIG. 5 the ball 268 and the knife 274 are shown in their operative positions wherein they are punching and cutting a sheet of plastic material represented at 296. The cylinder 238 is shown in its active position with its plunger 297 in its lowermost position bearing against the punch body 252. It will be noted that the spring 254 is compressed in the position shown. When the plunger 297 returns to its elevated position in the cylinder 238, the spring 254 returns the body 252 to an elevated position so that the ball 268 unseats from the cutting edge of the die button and the blade 274 rises out of the slot 294.

In FIG. 4 the two posts 224 of the units 220 and 222 are tied together by a graduated spacer bar 298 provided with a series of holes 299 through which screws may pass and attach to the upper surfaces of the posts 224. In FIG. 5 the spacer bar 298 is shown secured to the top of the post 224 by screw 300. If the holes 299 in the spacer bar 298 are graduated accurately, they may be used to accurately position the two punch units with respect to the plastic material fed through the machine.

- As in the previous embodiment, an impulse valve 106 is mounted on top of each cylinder 238, and as shown schematically in FIG. 5, the top of the valve 106 is connected to one manifold 302 through a gage 304 and pressure regulator 306. A second manifold 308 is connected to the control inlet 126 of the impulse valve, and a solenoid 310 controls the flow of compressed air to the manifold 308. Therefore, when the solenoid 310 is open, the manifold 308 is charged, which activates the impulse valve 126. In response to this the manifold 302 directs compressed air through the valve 106 to the cylinder 238 to activate the plunger 297. When the valve 310 closes, the pressure is relieved against the diaphragm in the impulse valve 106, and consequently the valve closes to disconnect the manifold 302 from the cylinder 238. Consequently, the spring (not shown) in the cylinder 238 returns the plunger to its elevated position. It will be understood and appreciated that the manifold 308 may control the impulse valves on both of the punch units so that both punch units are activated simultaneously, and the manifold 302 may be connected to each of the impulse valves so as to provide a driving charge for the cylinders.

From the foregoing description it will be appreciated that in each of the multi-punch assemblies shown the position of the punches may be adjusted to suit the particular needs of the fabricator. Further, a simple adjustment is provided in each of the punches to raise the die whenever necessary to insure clean punching of the stock. The simple pneumatic controls for the punches are virtually free of all complex parts so that the controls will have a long trouble free life.

From the foregoing description those skilled in the art willappreciate that numerous modifications may be made -of this invention without departing from its spirit. Therefore it is not intended to limit the breadth of this inventon to the specific embodiments illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.

What is claimed is:

1. A punch assembly comprising a frame having a pneumatic cylinder holder, a punch holder and a die holder,

a die mounted on the die holder and a punch mounted in its holder,

a pneumatic cylinder mounted on the pneumatic cylinder holder and when energized driving the punch toward the die holder, said die, punch and cylinder forming a punch unit,

a spring return mounted on the punch for returning the punch to a position away from the die holder when the cylinder is deenergized,

a passage for connecting the cylinder to a compressed air source,

an impulse valve in the passage and having an inlet and a control inlet,

means for maintaining the inlet of the impulse valve in communication with the source,

means including a second passage connecting the control inlet to a compressed air source, said control inlet when connected to the source opening the impulse valve to connect the inlet of the valve to the cylinder for energizing the cylinder,

and a control valve in the second passage for opening and closing the passage.

2. A punch assembly as defined in claim 1 further characterized by said punch including a body and a ball carried by the body,

and said die including a sleeve aligned with the ball and having a cutting edge cooperating with the ball for cutting round holes in stock fed through the punch.

3. A punch assembly as defined in claim 2 further characterized by a blade carried by the body,

and a slot in the die holder alinged with the blade for receiving the blade enabling the blade to pierce the stock when the ball and die cut round holes therein.

4. A punch assembly as defined in claim 1 further characterized by a second punch unit mounted on the frame and including another impulse valve connected to the cylinder of the second unit,

and means connecting the impulse valve of the second unit in parallel with the impulse valve of the first first unit so that the cylinders are simultaneously actuated to actuate their respective punches together.

5. A punch assembly as defined in claim 3 further characterized by a second punch unit mounted on the frame and including another impulse valve connected to the cylinder of the second unit,

and means connecting the impulse valve of the second unit in parallel with the impulse valve of the first first unit so that the cylinders are simultaneously actuated to actuate their respective punches together.

6. A multi-punch assembly comprising a frame having a plurality of sets of aligned holes provided therein for supporting punches, dies and pneumatic cylinders,

punches, dies and pneumatic cylinders mounted on the frame in the holes and suitable to be moved from one set of holes to another,

an impulse valve connected to each cylinder and having a control port which opens the valve when placed under pressure, each of said valves controlling the flow of air under pressure to its respective cylinder,

first means connected to the impulse valves for simultaneously impressing a pressure on the control ports o 1 i p e valve a and second means connected to the impulse valves for directing compressed air through the impulse valves to the cylinders when the impulse valves are opened.

'7. A multi-punch assembly comprising a frame,

a plurality of punch units including pneumatic cylinders mounted on the frame,

an impulse valve connected to each cylinder and having a control port which opens the valve when placed under pressure, each of said valves controlling the flow of air under pressure to its respective cylinder,

first means connected to the impulse valves for simultaneously impressing a pressure on the control ports of the impulse valves,

and second means connected to the impulse valves for directing compressed air through the impulse valves to the cylinders when the impulse valves are opened.

8. A multi-punch assembly as defined in claim 6 further characterized by said first means including a manifold with separate ducts connected between the manifold and each of the control ports,

and a line and control valve for connecting the manifold to a source of air under pressure for charging the manifold.

9. A multi-punch assembly as defined in claim 8 further characterized by said second means including a second manifold with separate ducts connected between the second manifold and some of the impulse valves for maintaining a charge of compressed air at the inlet side of the impulse valves.

10. In a multi-punoh assembly;

a frame,

a plurality of actuating cylinders mounted on the frame,

at least two manifolds disposed adjacent to the frame and connected to a compressed air source,

means including pneumatically controlled valves connecting one of the manifolds to each of the actuating cylinders for supplying compressed air to the cylinders to operate said cylinders,

and ducts connecting the other manifold to the pneumatically controlled valves to supply controlling air to the pneumatically controlled valves to open said valves.

11. A punch assembly comprising a frame lhavin g a punch holder and die holder,

a punch body slidably mounted in the punch holder and movable toward and away from the die holder,

a ball secured to the end of the punch body toward the die holder,

at sleeve-shaped die button mounted in the die holder and having a circular cutting edge in line with and engaged by the ball when the punch body is moved toward the die holder to cut a circular hole in sheet stock disposed between the die button and ball,

means for adjusting the position of the button in its hold to position it closer or further away from the punch body,

spring means secured to the body for yieldably urging the body away from the die holder,

and means operatively associated with the punch body for moving the body toward the die button and overcome the bias of the spring means.

12. A punch assembly as defined in claim 11 further characterized by a slot in the die holder adjacent the button,

and a blade carried by the body and aligned with the slot and entering the slot when the ball engages the button.

13. A punch assembly as defined in claim 12 further characterized by a second punch and die button mounted on the frame and substantially identical to the first described punch and die button,

9 10 and means for moving the two punches and die buttons machine enabling the bar to be adjustably positioned toward and away from each other. on the machine.

14. A punch assembly as defined in claim 13 further characterized by References Cited by the Examiner said frame including a mounting bar, 5 UNITED STATES PATENTS a pair of posts slidable on the mounting bar toward 3,089,376 5/1963 Whistler et a1 83*641 X and a from eachpther, 3,096,015 7/1963 Bradbury. and sa1d punch and die holders being mounted on the 3,098,406 7 /1963 Dodg6 et a1 5 X posts- 3,125,917 3/1964 Smeets 83685 X 15. A punch assembly as defined in claim 14 further 10 3,147,657 9/ 1964 Williamson 83 640 X characterlzed by 3,196,728 7/1965 Snow 83639 a pair of parallel rods slidably supporting the mounting bar and adapted to be connected to a bag making WILLIAM S. LAWSON, Primary Examiner. 

1. A PUNCH ASSEMBLY COMPRISING A FRAME HAVING A PNEUMATIC CYLINDER HOLDER, A PUNCH HOLDER AND A DIE HOLDER, A DIE MOUNTED ON THE DIE HOLDER AND A PUNCH MOUNTED IN ITS HOLDER, A PNEUMATIC CYLINDER MOUNTED ON THE PNEUMATIC CYLINDER HOLDER AND WHEN ENERGIZED DRIVING THE PUNCH TOWARD THE DIE HOLDER, SAID DIE, PUNCH AND CYLINDER FORMING A PUNCH UNIT, A SPRING RETURN MOUNTED ON THE PUNCH FOR RETURNING THE PUNCH TO A POSITION AWAY FROM THE DIE HOLDER WHEN THE CYLINDER IS DEENERGIZED, A PASSAGE FOR CONNECTING THE CYLINDER TO A COMPRESSED AIR SOURCE, 